Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Selection and gene flow shape niche-associated variation in pheromone response
Lee, Daehan ; Zdraljevic, Stefan ; Cook, Daniel E. ; Frézal, Lise ; Hsu, Jung-Chen ; Sterken, Mark G. ; Riksen, Joost A.G. ; Wang, John ; Kammenga, Jan E. ; Braendle, Christian ; Félix, Marie-Anne ; Schroeder, Frank C. ; Andersen, Erik C. - \ 2019
Nature Ecology & Evolution 3 (2019). - ISSN 2397-334X - p. 1455 - 1463.
From quorum sensing in bacteria to pheromone signalling in social insects, chemical communication mediates interactions among individuals in local populations. In Caenorhabditis elegans, ascaroside pheromones can dictate local population density; high levels of pheromones inhibit the reproductive maturation of individuals. Little is known about how natural genetic diversity affects the pheromone responses of individuals from diverse habitats. Here, we show that a niche-associated variation in pheromone receptor genes contributes to natural differences in pheromone responses. We identified putative loss-of-function deletions that impair duplicated pheromone receptor genes (srg-36 and srg-37), which were previously shown to be lost in population-dense laboratory cultures. A common natural deletion in srg-37 arose recently from a single ancestral population that spread throughout the world; this deletion underlies reduced pheromone sensitivity across the global C. elegans population. We found that many local populations harbour individuals with a wild-type or a deletion allele of srg-37, suggesting that balancing selection has maintained the recent variation in this pheromone receptor gene. The two srg-37 genotypes are associated with niche diversity underlying boom-and-bust population dynamics. We hypothesize that human activities likely contributed to the gene flow and balancing selection of srg-37 variation through facilitating the migration of species and providing a favourable niche for the recently arisen srg-37 deletion.

The Earth System Governance Project as a network organization: a critical assessment after ten years
Biermann, F. ; Betsill, Michele M. ; Burch, S. ; Dryzek, John ; Gordon, Christopher ; Gupta, A. ; Gupta, Joyeeta ; Inoue, Cristina ; Kalfagianni, Agni ; Kanie, Norichika ; Olsson, Lennart ; Persson, Åsa ; Schroeder, H. ; Scobie, Michelle - \ 2019
Current Opinion in Environmental Sustainability 39 (2019). - ISSN 1877-3435 - p. 17 - 23.

The social sciences have engaged since the late 1980s in international collaborative programmes to study questions of sustainability and global change. This article offers an in-depth analysis of the largest long-standing social-science network in this field: the Earth System Governance Project. Originating as a core project of the former International Human Dimensions Programme on Global Environmental Change, the Earth System Governance Project has matured into a global, self-sustaining research network, with annual conferences, numerous taskforces, research centers, regional research fellow meetings, three book series, an open access flagship journal, and a lively presence in social media. The article critically reviews the experiences of the Earth System Governance network and its integration and interactions with other programmes over the last decade.

Straightforward Regeneration of Reduced Flavin Adenine Dinucleotide Required for Enzymatic Tryptophan Halogenation
Ismail, Mohamed ; Schroeder, Lea ; Frese, Marcel ; Kottke, Tilman ; Hollmann, Frank ; Paul, Caroline E. ; Sewald, Norbert - \ 2019
ACS Catalysis 9 (2019)2. - ISSN 2155-5435 - p. 1389 - 1395.
enzymatic cofactor regeneration - FADH - flavin-dependent halogenases - hydride transfer - NADH mimics - regioselective chlorination

Flavin-dependent halogenases are known to regioselectively introduce halide substituents into aromatic moieties, for example, the indole ring of tryptophan. The process requires halide salts and oxygen instead of molecular halogen in the chemical halogenation. However, the reduced cofactor flavin adenine dinucleotide (FADH2) has to be regenerated using a flavin reductase. Consequently, coupled biocatalytic steps are usually applied for cofactor regeneration. Nicotinamide adenine dinucleotide (NADH) mimics can be employed stoichiometrically to replace enzymatic cofactor regeneration in biocatalytic halogenation. Chlorination of l-tryptophan is successfully performed using such NADH mimics. The efficiency of this approach has been compared to the previously established enzymatic regeneration system using the two auxiliary enzymes flavin reductase (PrnF) and alcohol dehydrogenase (ADH). The reaction rates of some of the tested mimics were found to exceed that of the enzymatic system. Continuous enzymatic halogenation reaction for reaction scale-up is also possible.

Environmental benefits of leaving offshore infrastructure in the ocean
Fowler, Ashley M. ; Jørgensen, A.M. ; Svendsen, Jon C. ; Macreadie, Peter I. ; Jones, Daniel O.B. ; Boon, Arjen R. ; Booth, David J. ; Brabant, Robin ; Callahan, Emily ; Claisse, Jeremy T. ; Dahlgren, Thomas G. ; Degraer, Steven ; Dokken, Quenton R. ; Gill, Andrew B. ; Johns, David G. ; Leewis, Robert J. ; Lindeboom, Han J. ; Linden, Olof ; May, Roel ; Murk, Albertinka J. ; Ottersen, Geir ; Schroeder, Donna M. ; Shastri, Sunil M. ; Teilmann, Jonas ; Todd, Victoria ; Hoey, Gert Van; Vanaverbeke, Jan ; Coolen, Joop W.P. - \ 2018
Frontiers in Ecology and the Environment 16 (2018)10. - ISSN 1540-9295 - p. 571 - 578.
The removal of thousands of structures associated with oil and gas development from the world’s oceans is well underway, yet the environmental impacts of this decommissioning practice remain unknown. Similar impacts will be associated with the eventual removal of offshore wind turbines. We conducted a global survey of environmental experts to guide best decommissioning practices in the North Sea, a region with a substantial removal burden. In contrast to current regulations, 94.7% of experts (36 out of 38) agreed that a more flexible case-by- case approach to decommissioning could benefit the North Sea environment. Partial removal options were considered to deliver better environmental outcomes than complete removal for platforms, but both approaches were equally supported for wind turbines. Key considerations identified for
decommissioning were biodiversity enhancement, provision of reef habitat, and protection from bottom trawling, all of which are negatively affected by complete removal. We provide recommendations to guide the revision of offshore decommissioning policy, including a temporary suspension of obligatory removal.
From pots to plots: Hierarchical trait-based prediction of plant performance in a mesic grassland
Schroeder, T.C. ; Wirth, C. ; Nadrowski, K. ; Meyer, S. ; Mommer, L. ; Weigelt, A. - \ 2016
Journal of Ecology 104 (2016)1. - ISSN 0022-0477 - p. 206 - 218.
Traits are powerful predictors of ecosystem functions pointing to underlying physiological and ecological processes. Plant individual performance results from the coordinated operation of many processes, ranging from nutrient uptake over organ turnover to photosynthesis, thus requiring a large set of traits for its prediction. For plant performance on higher hierarchical levels, e.g. populations, additional traits important for plant-plant and trophic interactions may be required which should even enlarge the spectrum of relevant predictor traits.(2)The goal of this study was to assess the importance of plant functional traits to predict individual and population performance of grassland species with particular focus on the significance of root traits. We tested this for 59 grassland species using 35 traits divided into three trait clusters: leaf traits (16), stature traits (8) and root traits (11), using individual biomass of mesocosm plants as a measure of individual performance and population biomass of monocultures as a measure of population performance. We applied structural equation models to disentangle direct effects of single traits on population biomass and indirect effects via individual plant biomass or shoot density.We tested multivariate trait effects on individual and population biomass to analyze whether the importance of different trait clusters shifts with increasing hierarchical integration from individuals to populations.(3)Traits of all three clusters significantly correlated with individual and population biomass. However, in spite of a number of significant correlations, above-below-ground linkages were generally week, with few exceptions like N content.(4)Stature traits exclusively affected population biomass indirectly via their effect on individual biomass, whereas root and leaf traits showed also direct effects and partly indirect effects via density.(5)The inclusion of root traits in multiple regression models improved the prediction of individual biomass compared to models with only above-ground information only slightly (95% vs. 93% of variance prediction with and without root traits, respectively) but was crucial for the prediction of population biomass (77% and 49%, respectively). Root traits were more important for plant performance than leaf traits and were even the most important predictors at the population level(6)Synthesis: Upscaling from the individual to the population level reflects an increasing number of processes requiring traits from different trait clusters for their prediction. Our results emphasize the importance of root traits for trait-based studies especially at higher organizational levels. Our approach provides a comprehensive framework acknowledging the hierarchical nature of trait influences. This is one step towards a more process-oriented assessment of trait-based approaches
Whole Genome SNP Discovery and Analysis of Genetic Diversity in Turkey (Meleagris gallopavo)
Aslam, M.L. ; Bastiaansen, J.W.M. ; Elferink, M.G. ; Megens, H.J.W.C. ; Crooijmans, R.P.M.A. ; Blomberg, L.A. ; Fleischer, R.C. ; Tassell, C.P. van; Sonstegard, T.S. ; Schroeder, S.G. ; Groenen, M. ; Long, Julie A. - \ 2014
PRJNA237339 - Meleagris gallopavo - SRP012021
Alignment of next generation sequencing data of 32 individual turkeys from different populations was used for the discovery of 5.49 million SNPs, and subsequent analysis of genetic diversity among the different populations. All of the commercial lines branched from a single node relative to the heritage varieties and the South Mexican turkey population. Heterozygosity of all individuals from the different turkey populations ranged from 0.17-2.73 SNPs/Kb, while heterozygosity of populations ranged from 0.73-1.64 SNPs/Kb. The average frequency of heterozygous SNPs in individual turkeys was 1.07 SNPs/Kb. Five genomic regions with very low nucleotide variation were identified in domestic turkeys that showed state of fixation towards alleles different than wild alleles.
Fewer invited talks by women in evolutionary biology sympsosia
Schroeder, J. ; Dugdale, H.L. ; Radersma, R. ; Hinsch, M. ; Buehler, D.M. ; Saul, J. ; Porter, L. ; Liker, A. ; Cauwer, I. de; Johnson, P.J. ; Santure, A.W. ; Griffin, A.S. ; Bolund, E. ; Ross, L. ; Webb, T.J. ; Feulner, P.G.D. ; Winney, I. ; Szulkin, M. ; Komdeur, J. ; Versteegh, M.A. ; Hemelrijk, C.K. ; Svensson, E.I. ; Edwards, H. ; Karlsson, M. ; West, S.A. ; Barrett, E.L.B. ; Richardson, D.S. ; Brink, V. van den; Wimpenny, J.H. ; Ellwood, S.A. ; Rees, M. van; Matson, K.D. - \ 2013
Journal of Evolutionary Biology 26 (2013)9. - ISSN 1010-061X - p. 2063 - 2069.
gender-differences - job applicants - science - recommendation - visibility - professors - female
Lower visibility of female scientists, compared to male scientists, is a potential reason for the under-representation of women among senior academic ranks. Visibility in the scientific community stems partly from presenting research as an invited speaker at organized meetings. We analysed the sex ratio of presenters at the European Society for Evolutionary Biology (ESEB) Congress 2011, where all abstract submissions were accepted for presentation. Women were under-represented among invited speakers at symposia (15% women) compared to all presenters (46%), regular oral presenters (41%) and plenary speakers (25%). At the ESEB congresses in 2001–2011, 9–23% of invited speakers were women. This under-representation of women is partly attributable to a larger proportion of women, than men, declining invitations: in 2011, 50% of women declined an invitation to speak compared to 26% of men. We expect invited speakers to be scientists from top ranked institutions or authors of recent papers in high-impact journals. Considering all invited speakers (including declined invitations), 23% were women. This was lower than the baseline sex ratios of early-mid career stage scientists, but was similar to senior scientists and authors that have published in high-impact journals. High-quality science by women therefore has low exposure at international meetings, which will constrain Evolutionary Biology from reaching its full potential. We wish to highlight the wider implications of turning down invitations to speak, and encourage conference organizers to implement steps to increase acceptance rates of invited talks.
Methodological ways of seeing and knowing
Yanow, D. - \ 2013
In: The Routledge Companion to Visual Organization / Bell, E., Warren, S., Schroeder, J.E., Oxford : Routledge (Routledge Companions in Business, Management and Accounting ) - ISBN 9780415783675 - p. 167 - 189.
Tolerance of Four Tropical Tree Species to Heavy Petroleum Contamination
Perez-Hernandez, I. ; Ochoa-Gaona, S. ; Schroeder, R.H.A. ; Rivera-Cruz, M.C. ; Geissen, V. - \ 2013
Water Air and Soil Pollution 224 (2013)8. - ISSN 0049-6979
soil-water relations - oxidative stress - bioremediated soils - seed-germination - end-point - phytoremediation - oil - hydrocarbons - growth - plants
Four species of trees were selected to evaluate the tolerance to heavy crude oil contamination by means of a tolerance index integrating germination, height, biomass and survival as variables. Fresh seeds to Cedrela odorata (tropical cedar), Haematoxylum campechianum (tinto bush), Swietenia macrophylla (mahogany) and Tabebuia rosea (macuilis) were planted in a Vertisol to which heavy crude petroleum was added at four different treatments (C0, 0; C1, 18,940; C2, 44,000; and C3, 57,000 mg kg(-1)), with the control being uncontaminated soil. The experiment was carried out in a greenhouse during 203 days with a completely random design. The presence of petroleum in soil stimulated and increased germination of S. macrophylla and C. odorata, accelerated the germination of T. rosea and did not affect the germination of H. campechianum. The height and biomass of all species was reduced in the presence of petroleum in the soil. The survival of S. macrophylla and H. campechianum was not affected by petroleum at any concentration studied. On the other hand, C. odorata and T. rosea showed high mortality at all concentrations. The tolerance index showed that S. macrophylla was best at tolerating petroleum in soil and could be employed as a productive alternative for the advantageous use of contaminated sites. The use of tree species could be important because of the great potential of trees for phytoremediation due to their long life, biomass and deep roots that can penetrate and remediate deeper soil layers.
Evaluation of classical swine fever virus antibody detection assays with an emphasis on the differentiation of infected from vaccinated animals
Schroeder, S. ; Rosen, T. von; Blome, S. ; Loeffen, W.L.A. ; Haegeman, A. ; Koenen, F. ; Uttenthal, A. - \ 2012
Revue scientifique et technique / Office International des Epizooties 31 (2012)3. - ISSN 0253-1933 - p. 997 - 1010.
The aim of this study was to evaluate the general characteristics of
commercially available enzyme-linked immunosorbent assays (ELISAs) to detect
antibody against classical swine fever (CSF), as well as to assess their potential
use as accompanying marker tests able to differentiate infected from vaccinated
animals (DIVA).
The Chekit* CSF-Sero and the HerdChek* CSFV Ab, both of which detect
antibodies against the E2 protein of classical swine fever virus (CSFV), had the
highest sensitivity. Both tests were practicable and showed good reproducibility.
Comparable sensitivity was shown by the Chekit* CSF-Marker, an Erns ELISA.
However, this test does not allow differentiation between antibodies directed
against ruminant pestiviruses and those against CSFV. Therefore, it is not
suitable for use with the chimeric marker vaccines tested.
The PrioCHECK® CSFV Erns was the only ELISA suitable for use in DIVA with
marker vaccines containing Erns proteins from ruminant pestiviruses. However,
this test was less sensitive and selective than the E2-ELISAs and cannot be
recommended.
Whole genome SNP discovery and analysis of genetic diversity in Turkey (Meleagris gallopavo)
Aslam, M.L. ; Bastiaansen, J.W.M. ; Elferink, M.G. ; Megens, H.J.W.C. ; Crooijmans, R.P.M.A. ; Blomberg, L.A. ; Fleischer, R.C. ; Tassell, C.P. van; Sonstegard, T.S. ; Schroeder, S.G. ; Groenen, M. ; Long, J.A. - \ 2012
BMC Genomics 13 (2012). - ISSN 1471-2164
single-nucleotide polymorphisms - breast meat yield - linkage disequilibrium - evolutionary genomics - sequencing technology - body-composition - holstein cattle - farm-animals - dna analysis - chicken
Background The turkey (Meleagris gallopavo) is an important agricultural species and the second largest contributor to the world’s poultry meat production. Genetic improvement is attributed largely to selective breeding programs that rely on highly heritable phenotypic traits, such as body size and breast muscle development. Commercial breeding with small effective population sizes and epistasis can result in loss of genetic diversity, which in turn can lead to reduced individual fitness and reduced response to selection. The presence of genomic diversity in domestic livestock species therefore, is of great importance and a prerequisite for rapid and accurate genetic improvement of selected breeds in various environments, as well as to facilitate rapid adaptation to potential changes in breeding goals. Genomic selection requires a large number of genetic markers such as e.g. single nucleotide polymorphisms (SNPs) the most abundant source of genetic variation within the genome. Results Alignment of next generation sequencing data of 32 individual turkeys from different populations was used for the discovery of 5.49 million SNPs, which subsequently were used for the analysis of genetic diversity among the different populations. All of the commercial lines branched from a single node relative to the heritage varieties and the South Mexican turkey population. Heterozygosity of all individuals from the different turkey populations ranged from 0.17-2.73 SNPs/Kb, while heterozygosity of populations ranged from 0.73-1.64 SNPs/Kb. The average frequency of heterozygous SNPs in individual turkeys was 1.07 SNPs/Kb. Five genomic regions with very low nucleotide variation were identified in domestic turkeys that showed state of fixation towards alleles different than wild alleles. Conclusion The turkey genome is much less diverse with a relatively low frequency of heterozygous SNPs as compared to other livestock species like chicken and pig. The whole genome SNP discovery study in turkey resulted in the detection of 5.49 million putative SNPs compared to the reference genome. All commercial lines appear to share a common origin. Presence of different alleles/haplotypes in the SM population highlights that specific haplotypes have been selected in the modern domesticated turkey
Transforming governance and institutions for global sustainability: key insights from the Earth System Governance Project
Biermann, F. ; Abbott, K. ; Andresen, S. ; Bäckstrand, K. ; Bernstein, S. ; Betsill, M.M. ; Bulkeley, H. ; Cashore, B. ; Clapp, J. ; Folke, C. ; Gupta, A. ; Gupta, J. ; Haas, P.M. ; Jordan, A. ; Kanie, N. ; Kluvánková-Oravská, T. ; Lebel, L. ; Liverman, D. ; Meadowcroft, J. ; Mitchell, R.B. ; Newell, P. ; Oberthür, S. ; Olsson, L. ; Pattberg, P. ; Sánchez-Rodriguez, R. ; Schroeder, H. ; Underdal, A. ; Camargo Vieira, S. ; Vogel, C. ; Young, O.R. ; Brock, A. ; Zondervan, R. - \ 2012
Current Opinion in Environmental Sustainability 4 (2012)1. - ISSN 1877-3435 - p. 51 - 60.
social-ecological systems - environmental governance - climate-change - information disclosure - adaptive governance - regime complex - world - decentralization - accountability - transparency
The current institutional framework for sustainable development is by far not strong enough to bring about the swift transformative progress that is needed. This article contends that incrementalism—the main approach since the 1972 Stockholm Conference—will not suffice to bring about societal change at the level and speed needed to mitigate and adapt to earth system transformation. Instead, the article argues that transformative structural change in global governance is needed, and that the 2012 United Nations Conference on Sustainable Development in Rio de Janeiro must turn into a major stepping stone for a much stronger institutional framework for sustainable development. The article details core areas where urgent action is required. The article is based on an extensive social science assessment conducted by 32 members of the lead faculty, scientific steering committee, and other affiliates of the Earth System Governance Project. This Project is a ten-year research initiative under the auspices of the International Human Dimensions Programme on Global Environmental Change (IHDP), which is sponsored by the International Council for Science (ICSU), the International Social Science Council (ISSC), and the United Nations University (UNU)
Navigating the Anthropocene: Improving Earth System Governance
Biermann, F. ; Abbott, K. ; Andresen, S. ; Bäckstrand, K. ; Bernstein, S. ; Betsill, M.M. ; Bulkeley, H. ; Cashore, B. ; Clapp, J. ; Folke, C. ; Gupta, A. ; Gupta, J. ; Haas, P.M. ; Jordan, A. ; Kanie, N. ; Kluvánková-Oravská, T. ; Lebel, L. ; Liverman, D. ; Meadowcroft, J. ; Mitchell, R.B. ; Newell, P. ; Oberthür, S. ; Olsson, L. ; Pattberg, P. ; Sánchez-Rodriguez, R. ; Schroeder, H. ; Underdal, A. ; Camargo Vieira, S. ; Vogel, C. ; Young, O.R. ; Brock, A. ; Zondervan, R. - \ 2012
Science 335 (2012)6074. - ISSN 0036-8075 - p. 1306 - 1307.
Science assessments indicate that human activities are moving several of Earth's sub-systems outside the range of natural variability typical for the previous 500,000 years (1, 2). Human societies must now change course and steer away from critical tipping points in the Earth system that might lead to rapid and irreversible change (3). This requires fundamental reorientation and restructuring of national and international institutions toward more effective Earth system governance and planetary stewardship
Impact of the European Clinical Trials Directive on prospective academic clinical trials associated with BMT
Frewer, L.J. ; Coles, D.G. ; Lans, I.A. van der; Schroeder, D. ; Champion, K. ; Apperley, J.F. - \ 2011
Bone Marrow Transplantation 46 (2011). - ISSN 0268-3369 - p. 443 - 447.
The European Clinical Trials Directive (EU 2001; 2001/20/EC) was introduced to improve the efficiency of commercial and academic clinical trials. Concerns have been raised by interested organizations and institutions regarding the potential for negative impact of the Directive on non-commercial European clinical research. Interested researchers within the European Group for Blood and Marrow Transplantation (EBMT) were surveyed to determine whether researcher experiences confirmed this view. Following a pilot study, an internet-based questionnaire was distributed to individuals in key research positions in the European haemopoietic SCT community. Seventy-one usable questionnaires were returned from participants in different EU member states. The results indicate that the perceived impact of the European Clinical Trials Directive has been negative, at least in the research areas of interest to the EBMT
Factors Impacting Food Safety Risk Perceptions
Tonsor, G.T. ; Schroeder, T.C. ; Pennings, J.M.E. - \ 2009
Journal of Agricultural Economics 60 (2009)3. - ISSN 0021-857X - p. 625 - 644.
mad-cow-disease - perceived risk - health risks - trust - information - preferences - behavior - attitude - determinants - acceptance
We developed and applied a model of consumer risk perceptions of beef food safety to better understand the underlying drivers of consumer demand for food safety. We show how consumer demographics, country-of-residence, as well as reliance on, and trust in, alternative food safety information sources affect risk perceptions of consumers in Canada, Japan and the United States. Consumers in all three countries have risk perceptions shaped by their level of reliance on observable and credence attribute information. Risk perceptions of consumers in each country are significantly higher for those less trusting of doctors. Moreover, personal and indirect food safety experiences substantially affect risk perceptions. These results are useful to decision-makers in developing more efficient supply chain management strategies and public policies aimed at building or sustaining consumer confidence in food safety
Consumer Valuations of Beef Steak Food Safety Enhancement in Canada, Japan, Mexico, and the United States
Tonsor, G.T. ; Schroeder, T.C. ; Pennings, J.M.E. ; Mintert, J. - \ 2009
Canadian Journal of Agricultural Economics 57 (2009)3. - ISSN 0008-3976 - p. 395 - 416.
willingness-to-pay - appliance efficiency level - mixed logit model - contingent valuation - choice experiments - cheap talk - preferences - demand - design - us
Food safety concerns have had dramatic impacts on food and livestock markets in recent years. We examine consumer preferences for beef steak food safety assurances. We evaluate the extent to which preferences are heterogeneous within and across country-of-residence defined groups and examine the distributional nature of preferences with respect to marginal improvements in food safety. Using mixed logit models, we find that consumers in Canada, Japan, Mexico, and the United States have willingness to pay preferences that are nonlinear in the level of food safety risk reduction. In particular, consumers in Japan and Mexico have preferences that are convex and consumers in Canada and the United States have preferences concave in the level of food safety enhancement. Les inquiétudes entourant la sécurité alimentaire ont eu des répercussions considérables sur le marché du bétail et le marché des aliments au cours des derni`eres années. Nous avons examiné les préférences des consommateurs concernant l’assurance de la sécurité alimentaire de la viande de boeuf. Nous avons évalué dans quelle mesure les préférences des consommateurs étaient hétérog`enes au sein de groupes établis selon le pays de résidence et entre ces groupes, et avons examiné la nature distributionnelle des préférences à l’égard des améliorations marginales de la sécurité alimentaire. L’utilisation de modèles logit mixtes nous a permis d’établir que la volonté de payer des consommateurs du Canada, du Japon, du Mexique et des États-Unis étaient non linéaires lorsqu’il était question de diminuer le degré de risque concernant la sécurité alimentaire. Les préférences des consommateurs du Japon et du Mexique étaient convexes, tandis que celles des consommateurs du Canada et des États-Unis étaient concaves lorsqu’il était question d’accroître le niveau de sécurité alimentaire
Autosomal and sex-linked microsatellite loci in the green oak leaf roller Tortrix viridana L.
Schroeder, H.C. ; Arens, P.F.P. ; Smulders, M.J.M. - \ 2009
Molecular Ecology Resources 9 (2009)3. - ISSN 1755-098X - p. 809 - 811.
identification - markers
Eight microsatellite markers were developed for the lepidopteran species Tortrix viridana using an enrichment protocol. The loci were highly variable with number of alleles ranging from four to 38. Six of the eight loci were in Hardy¿Weinberg equilibrium. The other two were linked to the Z-chromosome. Values of observed heterozygosity ranged for the autosomal loci from 0.510 to 0.957. All loci will be useful to study dispersal and the autosomal loci, as well for phylogeographical studies.
A review of pesticide policies and regulations for urban amenity areas in seven European countries
Kristoffersen, P. ; Rask, A.M. ; Grundy, A. ; Franzen, I. ; Kempenaar, C. ; Raisio, J. ; Schroeder, H. ; Spijker, J.H. ; Verschwele, A. ; Zarina, L. - \ 2008
Weed Research 48 (2008). - ISSN 0043-1737 - p. 201 - 214.
nonchemical weed-control - hard surfaces - denmark - water
An analysis of the regulations of herbicide use for weed control in non-agricultural/urban amenity areas, including actual pesticide use, was carried out as a joint survey of seven European countries: Denmark, Finland, Germany, Latvia, the Netherlands, Sweden and United Kingdom. Herbicides constitute the major part of the pesticides used in urban amenity areas. Herbicide use on hard surfaces is the largest in terms of volume and potential contamination of surface and groundwater. The aim of the study was to investigate the differences in political interest and public debate on the 'use of pesticides in public urban amenity areas', regulations within each country at national, regional and local levels, possible use of alternative weed control methods and the amounts of pesticides used on urban amenity areas. A comparative analysis revealed major differences in political interest, regulations and availability of statistics on pesticide use. Denmark, Sweden, the Netherlands and Germany have, or have had, a strong public and political interest for reducing the use of herbicides to control weeds in urban amenity areas and also have very strict regulations. The UK is currently undergoing a period of increasing awareness and strengthening regulation, while Latvia and Finland do not have specific regulations for weed control in urban amenity areas or on hard surfaces. Statistics on pesticide/herbicide use on urban amenity areas were only available in Denmark and the Netherlands. Developing this kind of information base reveals the differences in herbicide use, regulations and policies in European countries and may enhance the transfer of knowledge on sustainable weed control across countries.
The Role of Consumer risk Perceptions and Attitudes in Cross Cultural Beef Consumptions Changes
Schroeder, T.C. ; Tonsor, G.T. ; Pennings, J.M.E. ; Mintert, J. - \ 2007
- p. 1 - 35.
Abstract Beef food safety events have contributed to considerable market volatility, produced varied consumer reactions, created policy debates, sparked heated trade disputes, and generally contributed to beef industry frustrations. Better understanding of the forces causing observed consumer reactions in light of beef food safety events is critical for policy makers and industry participants. We examine whether consumers altered their beef consumption behavior because of their risk aversion and risk perceptions stemming from information about beef food safety in recent years. We use data from a total of 4,000 consumers in the U.S., Canada, Mexico and Japan to estimate a two-stage Probit/double-bounded Tobit modeling framework. Results reveal there are stark differences in risk perceptions and risk aversion regarding beef food safety across consumers in the four countries and that these differences are revealed through different beef consumption behavior. An improved understanding of food safety perceptions and attitudes will enable policy makers and agricultural industries to better anticipate consumers changing consumption behavior, if a food safety event occurs. Consumers from the four countries examined exhibited heterogeneous food safety perceptions and attitudes. Results suggest that food safety management strategies should vary across countries because of identified differences in food safety risk attitudes and risk perceptions. Keywords: Cross-culture; risk attitude, risk perception, food safety, beef
Consumers Valuations and choice Processes of Food Safety Enhancement Attributes: An International Study of Beef Consumers
Tonsor, G.T. ; Schroeder, T.C. ; Pennings, J.M.E. ; Mintert, J. - \ 2007
- p. 1 - 31.
Abstract Food safety concerns have had dramatic impacts on food and livestock markets in recent years. Here we examine consumer preferences for various beef food safety assurances. In particular, we evaluate the extent to which such preferences are heterogeneous within and across country-of-residence defined groups and examine the distributional nature of these preferences with respect to marginal improvements in food safety. We collected data from over 4,000 U.S., Canada, Japan, and Mexican consumers. Using mixed logit models we find that Japanese and Mexican consumers have WTP preferences that are nonlinear in the level of food safety risk reduction. Conversely, U.S .and Canadian consumers appear to possess linear preferences. These results suggest that optimal food safety investment strategies hinge critically upon consumer perception of actual food safety improvements, the distributional relationship describing the targeted consumer segment¿s tradeoff function between WTP premiums and risk reduction levels, and the cost structure of these investments. Keywords: consumer beef preference, food safety, investment decision, mixed logit, willingness-to-pay
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